Bowen and Rovira (1966) have shown in short-term uptake studies that nonsterile clover and tomato plants took up 45 and 85% respectively more phosphate than did sterile plants. Not only was total uptake of phosphate increased in the presence of the rhizoplane microorganisms but translocation of absorbed phosphate to the tops was 4�4 times greater in the non-sterile tomato plants.